1 in 5 US Adolescents Is Pre-diabetic, Says Study. Conducted by researchers affiliated with the Centers for Disease Control (CDC), the study was published in 'JAMA Pediatrics.'. In addition to the alarming statistic concerning adolescents, it found that almost 25% of young adults in the U.S. are also pre-diabetic. The condition means that the person has high blood sugar levels, though not high enough for a Type 2 diabetes diagnosis. Type 2 diabetes has been linked to obesity. People with the con